The present invention is directed to a drill, which can be a multi-purpose drill used for drilling masonry as well as a drill for drilling wood or metal.
The greatest significance is accorded to a spiral or twist drill among drill tools, since it is considered the most important tool when producing cylindrical holes from a solid or for enlarging a predetermined hole diameter during a drilling operation. Its share of metal-cutting fabrication is estimated between 20% and 25%, and it is currently the metal-cutting tool that is produced in the greatest piece numbers and is most wide-spread. Viewed in simple fashion, a spiral drill is composed of a drill head, a drill shank that comprises a conveying helix and a plug-in end. What is referred to as a "double-thread" conveying helix is formed by two flutes or grooves arranged offset by 180.degree.. The two-thread conveying helices fashioned in this way can buckle during drilling and lead to unstable drilling behavior.